Natural gas is not a toxic substance when inhaled. However, exposure to high levels depletes the oxygen level in the body, which gives rise to cognitive problems. In the earlier stages, you may experience dizziness, headaches and blurred vision. Continued exposure may result in memory loss, disorientation and poor judgment. In severe cases, you may begin to hallucinate. This is what we are now observing in the Eastern Mediterranean, which has recently attracted increased industry and international attention following a series of major natural gas discoveries offshore Israel and Cyprus.